Hydrogenated block copolymer and composition thereof

Abstract

An object of the present invention is to provide a hydrogenated block copolymer having excellent flexibility, heat resistance, abrasion resistance and surface texture (no stickiness, oil bleeding etc.) and good processability, and a composition thereof. The present invention provides a hydrogenated block copolymer that has therein at least one of each of a vinyl aromatic compound polymer block A, a hydrogenated polymer block B of a random copolymer comprising a conjugated diene and a vinyl aromatic compound, and a hydrogenated polymer block C of a conjugated diene polymer having a vinyl bond content of not less than 30%, the hydrogenated block copolymer having a vinyl aromatic compound content of more than 50 wt % and less than 95 wt %, and a composition containing the hydrogenated block copolymer.

1. A hydrogenated block copolymer that is a hydrogenated material of a copolymer comprising a conjugated diene and a vinyl aromatic compound, and has following properties (1) to (6):
 (1) the hydrogenated block copolymer has therein at least one of each of following polymer blocks a, b, and c: 
 a. a vinyl aromatic compound polymer block A, 
 b. a hydrogenated polymer block B of a random copolymer comprising a conjugated diene and a vinyl aromatic compound, and 
 c. a hydrogenated polymer block C of a conjugated diene homopolymer having a vinyl bond content of not less than 30% obtained by adding conjugated diene monomers to a product of a polymerization of at least one of polymer blocks a and b; 
 (2) the hydrogenated block copolymer has a vinyl aromatic compound content of more than 58 wt % and less than 95 wt %; 
 (3) the hydrogenated block copolymer has a weight average molecular weight in a range of from 50,000 to 1,000,000; 
 (4) a vinyl bond content of conjugated diene monomer units constituting a polymer of the hydrogenated polymer block B before hydrogenation is not less than 10% and less than 20%; 
 (5) a double bond hydrogenation ratio of the conjugated diene monomer units is not less than 75%; and 
 (6) the hydrogenated block copolymer has the vinyl aromatic compound polymer block A content in a range of from 25 to 50 wt %, the hydrogenated copolymer block B content in a range of from 30 to 80 wt %, and the hydrogenated polymer block C content in a range of from 10 to 35 wt %. 
 
     
     
       2. The hydrogenated block copolymer according to  claim 1 , wherein the hydrogenated polymer block C content is in a range of from 10 to 30 wt %. 
     
     
       3. The hydrogenated block copolymer according to  claim 1 , having therein at least two of the vinyl aromatic compound polymer blocks A. 
     
     
       4. The hydrogenated block copolymer according to  claim 3 , having the vinyl aromatic compound polymer blocks A at each end thereof. 
     
     
       5. The hydrogenated block copolymer according to  claim 1 , wherein the hydrogenated block copolymer is further bonded to a functional group-containing atomic group. 
     
     
       6. A hydrogenated block copolymer composition comprising (1) 100 parts by weight of the hydrogenated block copolymer according to  claim 1 , and (2) from 5 to 100 parts by weight of a rubber-softening agent. 
     
     
       7. The hydrogenated block copolymer composition according to  claim 6 , wherein there is at least one tan δ (loss tangent) peak in a range of from 0 to 40° C. in a viscoelasticity measurement chart obtained for the hydrogenated block copolymer composition. 
     
     
       8. A hydrogenated block copolymer composition comprising (1) 100 parts by weight of the hydrogenated block copolymer according to a  claim 1 , (2) from 5 to 100 parts by weight of a rubber-softening agent, and (3) from 5 to 100 parts by weight of a thermoplastic resin and/or a rubbery polymer. 
     
     
       9. A hydrogenated block copolymer composition comprising:
 (a) the hydrogenated block copolymer according to  claim 1  as a first material; 
 (b) a second material formed of a hydrogenated block copolymer that is obtained by hydrogenating a block copolymer comprising at least two polymer blocks D composed mainly of a vinyl aromatic compound and at least one polymer block E composed mainly of a conjugated diene, and that has following properties (7) to (9): 
 (7) the hydrogenated block copolymer of the second material has a total vinyl aromatic compound content in a range of from 10 to 40 wt %, and a proportion of the polymer blocks D composed mainly of the vinyl aromatic compound out of the total vinyl aromatic compound content is not less than 80 wt %; 
 (8) the hydrogenated block copolymer of the second material has a weight average molecular weight in a range of from 200,000 to 600,000; and 
 (9) not less than 75% of double bonds of the conjugated diene monomer unit in the hydrogenated block copolymer of the second material are hydrogenated; 
 (c) a thermoplastic resin; and 
 (d) a rubber softening agent; 
 wherein, relative to 100 parts by weight in total of the components (a) and (b), the component (c) content is in a range of from 20 to 200 parts by weight, and the rubber softening agent content is in a range of from 20 to 250 parts by weight. 
 
     
     
       10. The hydrogenated block copolymer composition according to  claim 9 , wherein the thermoplastic resin comprises at least one polyolefin resin. 
     
     
       11. The hydrogenated block copolymer composition according to  claim 9 , further comprising from 0.1 to 10 parts by weight of an organopolysiloxane per 100 parts by weight of the hydrogenated block copolymer composition. 
     
     
       12. The hydrogenated block copolymer composition according to  claim 11 , wherein the organopolysiloxane is a liquid polydimethylsiloxane, and has a kinematic viscosity at 25° C. of not less than 90 cst. 
     
     
       13. The hydrogenated block copolymer composition according to  claim 9 , having an MFR at 230° C. and 2.16 kg in a range of from 0.1 to 100 g/10 min, and an impact resilience at 23° C. of not more than 40%. 
     
     
       14. The hydrogenated block copolymer according to  claim 2 , having therein at least two of the vinyl aromatic compound polymer blocks A. 
     
     
       15. The hydrogenated block copolymer according to  claim 14 , having the vinyl aromatic compound polymer blocks A at each end thereof. 
     
     
       16. The hydrogenated block copolymer according to  claim 15 , wherein the hydrogenated block copolymer is further bonded to a functional group-containing atomic group. 
     
     
       17. A hydrogenated block copolymer composition comprising (1) 100 parts by weight of the hydrogenated block copolymer according to  claim 16 , and (2) from 5 to 100 parts by weight of a rubber-softening agent. 
     
     
       18. The hydrogenated block copolymer composition according to  claim 17 , wherein there is at least one tan δ (loss tangent) peak in a range of from 0 to 40° C. in a viscoelasticity measurement chart obtained for the hydrogenated block copolymer composition. 
     
     
       19. A hydrogenated block copolymer composition comprising (1) 100 parts by weight of the hydrogenated block copolymer according to  claim 16 , (2) from 5 to 100 parts by weight of a rubber-softening agent, and (3) from 5 to 100 parts by weight of a thermoplastic resin and/or a rubbery polymer. 
     
     
       20. A hydrogenated block copolymer composition comprising:
 (a) the hydrogenated block copolymer according to  claim 16  as a first material; 
 (b) a second material formed of a hydrogenated block copolymer that is obtained by hydrogenating a block copolymer comprising at least two polymer blocks D composed mainly of a vinyl aromatic compound and at least one polymer block E composed mainly of a conjugated diene, and that has following properties (7) to (9): 
 (7) the hydrogenated block copolymer of the second material has a total vinyl aromatic compound content in a range of from 10 to 40 wt %, and a proportion of the polymer blocks D composed mainly of the vinyl aromatic compound out of the total vinyl aromatic compound content is not less than 80 wt %; 
 (8) the hydrogenated block copolymer of the second material has a weight average molecular weight in a range of from 200,000 to 600,000; and 
 (9) not less than 75% of double bonds of the conjugated diene monomer unit in the hydrogenated block copolymer of the second material are hydrogenated; 
 (c) a thermoplastic resin; and 
 (d) a rubber softening agent; 
 wherein, relative to 100 parts by weight in total of the components (a) and (b), the component (c) content is in a range of from 20 to 200 parts by weight, and the rubber softening agent content is in a range of from 20 to 250 parts by weight. 
 
     
     
       21. The hydrogenated block copolymer composition according to  claim 20 , wherein the thermoplastic resin comprises at least one polyolefin resin. 
     
     
       22. The hydrogenated block copolymer composition according to  claim 21 , further comprising from 0.1 to 10 parts by weight of an organopolysiloxane per 100 parts by weight of the hydrogenated block copolymer composition. 
     
     
       23. The hydrogenated block copolymer composition according to  claim 22 , wherein the organopolysiloxane is a liquid polydimethylsiloxane, and has a kinematic viscosity at 25° C. of not less than 90 cst. 
     
     
       24. The hydrogenated block copolymer composition according to  claim 23 , having an MFR at 230° C. and 2.16 kg in a range of from 0.1 to 100 g/10 min, and an impact resilience at 23° C. of not more than 40%.